Late maturation of backward masking in auditory cortex

Late maturation of backward masking in auditory cortex Mattingly Donell Rosen

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Late maturation of backward masking in auditory cortex 2018 Journal of Neurophysiology 10.1152/jn.00114.2018 Mattingly2018-late-maturation-of-backward-masking-in-audit Mattingly2018-late-maturation-of-backward-masking-in-audit.txt, the project's staged copy 4b0007e419efaf2020671f0667b980eecbc53b4c not-redistributable neuroscience

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0 spans located by searching the stored text for the quote's exact words, allowing any whitespace between them the cortical basis of auditory backward masking, and whether its unusually long maturation in children is visible in cortical responses Quotation withheld because this record is not cleared for redistribution. whether standard onset-responsive cortical neurons show backward masking at all, and whether juveniles show more of it than adults Quotation withheld because this record is not cleared for redistribution. backward masking is present in ordinary cortical neurons, arises from both suppressed tone firing and a reduced dynamic range, and is larger in juveniles - mainly through the suppression Quotation withheld because this record is not cleared for redistribution. mechanism Quotation withheld because this record is not cleared for redistribution. auditory backward masking Quotation withheld because this record is not cleared for redistribution. electrophysiology electrophysiology Quotation withheld because this record is not cleared for redistribution. mechanisms Inhibition evoked by the masker arrives with a shorter latency than excitation, so it can reach back and suppress the response to the tone that preceded it. Quotation withheld because this record is not cleared for redistribution. mechanisms In immature cortex the inhibitory response to the masker is larger and slower to decay, so it truncates more of the preceding excitatory tone response and amplifies firing-rate suppression in juveniles. Quotation withheld because this record is not cleared for redistribution. mechanisms Juveniles integrate over a longer listening window, which pulls more masker-driven firing into the comparison baseline, shrinking the dynamic range and raising masked thresholds. Quotation withheld because this record is not cleared for redistribution. mechanisms Unrefined inhibition in cortex or in presynaptic regions lets an off-frequency noise masker suppress juvenile responses more than adult ones. Quotation withheld because this record is not cleared for redistribution. masking arises from a reduction of the signal response together with a higher comparative baseline, which narrows the dynamic range available for detection Quotation withheld because this record is not cleared for redistribution. and a shorter latency for inhibition than for excitation lets the later masker suppress the earlier tone, which also explains why a suppressed masker response masks less Quotation withheld because this record is not cleared for redistribution. so the cortical effect may be inherited from earlier regions, with cortex possibly adding to it by reducing rebound excitation Quotation withheld because this record is not cleared for redistribution. and the immature version is attributed to inhibition that decays more slowly and summates more in young neurons Quotation withheld because this record is not cleared for redistribution. Recordings were made under anesthesia, which complicates extrapolation to psychophysics. what this limits: the comparison with psychophysics only: ANESTHESIA IS ONE CONCERN IN EXTENDING OUR NEURAL RESPONSES TO PSYCHOPHYSICAL COMPARISONS Quotation withheld because this record is not cleared for redistribution. It is unknown whether the nervous system actually reads out only the narrow tone-response window the analysis assumes. what this limits: the readout assumption behind every ToneWin result: IT IS UNKNOWN WHETHER THE NERVOUS SYSTEM IS ANALYZING ACTIVITY ONLY WITHIN THIS WINDOW Quotation withheld because this record is not cleared for redistribution. The population neurometric pools every recorded cell, which is both its strength and its weakness. what this limits: every population-neurometric result: IT POOLS INFORMATION ACROSS ALL CELLS TO MAKE A DECISION FOR OR AGAINST TONE DETECTION - stated by the authors as strength and limitation Quotation withheld because this record is not cleared for redistribution. Including non-responsive neurons should degrade the pooled neurometric, and whether that degradation is age-dependent is unknown. what this limits: the absolute level of the neurometric, and the age comparison it feeds: PERFORMANCE ... SHOULD BE REDUCED BY INCORPORATING RESPONSES FROM NONRESPONSIVE NEURONS, BUT WHETHER THIS EFFECT WOULD VARY ACROSS AGE is unknown Quotation withheld because this record is not cleared for redistribution. Single units and multiunits were pooled because multiunits dominated the dataset. what this limits: any claim resting on single-unit resolution: Quotation withheld Quotation withheld because this record is not cleared for redistribution. it is unknown whether the nervous system analyses only the narrow window, and finding out would require trial-by-trial mapping of activity onto behavioral choice what this limits: the same scope as limitations[1] - the analysis window is the experimenter's, not shown to be the nervous system's Quotation withheld because this record is not cleared for redistribution. the population neurometric pools every cell, which is both its strength and its limitation, and sits against the rival principle that only the most sensitive neurons matter what this limits: the same scope as limitations[2] - the pooled neurometric Quotation withheld because this record is not cleared for redistribution. and because every neuron was tested at its own best frequency, the pooled measure is optimistic in a way the paper spells out what this limits: the absolute performance of the neurometric, which is optimistic by construction: BECAUSE ALL NEURONS ... WERE PRESENTED WITH STIMULI AT BF, OUR NEUROMETRIC DOES NOT REFLECT THE SITUATION WHERE A DOWNSTREAM INTEGRATOR NEURON WOULD ALSO RECEIVE INPUT FROM other cells Quotation withheld because this record is not cleared for redistribution. anesthesia is named as a concern for the comparison with psychophysics, with urethane chosen to keep the cortex closest to the awake state what this limits: the same scope as limitations[0] - the psychophysical comparison, with urethane chosen deliberately Quotation withheld because this record is not cleared for redistribution. and the authors' own earlier null on the best neurons suggests the difference may lie in how the information is used rather than in how it is encoded what this limits: the interpretation of the age effect: the authors' own earlier study OBSERVED NO AGE DIFFERENCE IN THE THRESHOLDS OF THE BEST NEURONS, so the difference may be in pooling rather than in single-neuron sensitivity Quotation withheld because this record is not cleared for redistribution. The two-alternative forced-choice detection procedure and threshold-shift logic of human masking experiments is carried over to single-unit spike counts as a neurometric, so that neural thresholds can be compared directly with psychometric ones. Quotation withheld because this record is not cleared for redistribution. the masked-versus-unmasked threshold comparison, reproduced in the neurometric so the two can be put side by side Quotation withheld because this record is not cleared for redistribution. the encoding time window as an explicit parameter, and the requirement to choose one Quotation withheld because this record is not cleared for redistribution. population coding, which assumes that all active neurons contribute to perception, against the lower envelope principle, which assumes that perception is driven by the most sensitive neurons Quotation withheld because this record is not cleared for redistribution. the relative-timing-of-inhibition account of masking Quotation withheld because this record is not cleared for redistribution. a SECOND analysis window spanning the entire trial, beside the assumption-bearing one eliminates: the choice of time window as the driver of the result - a window chosen to capture an expected effect will find it · outcome (stated by the tagger, no quotation): held Quotation withheld because this record is not cleared for redistribution. masker masker Quotation withheld because this record is not cleared for redistribution. threshold threshold Quotation withheld because this record is not cleared for redistribution. dynamic range dynamic range Quotation withheld because this record is not cleared for redistribution. juvenile juvenile Quotation withheld because this record is not cleared for redistribution. MUs → analysis AN ANALYST DECISION WITH ITS REASON GIVEN: because multiunits dominated the data set, all single units and multiunits were POOLED for analysis. The composition is 15 SU / 27 MU in adults and 10 SU / 30 MU in juveniles, so the pooling decision is load-bearing for every comparison that follows. No edge type records a choice the analysts made. Quotation withheld because this record is not cleared for redistribution. THE ANALYSIS WINDOW IS A CHOICE, AND THE REASONS ARE GIVEN BEFORE THE RESULT: a brief window isolates backward masking uncontaminated by forward masking, a longer one includes the masker response because behavioral reaction times fall well after masker onset Quotation withheld because this record is not cleared for redistribution. AND THE TWO WINDOWS GIVE DIFFERENT NUMBERS: about 18 to 43 dB of threshold shift in the longer window against 13 to 16 dB in the narrow one, with human psychophysics at 20 to 35 dB Quotation withheld because this record is not cleared for redistribution. THE CORRECT WINDOW CANNOT BE DETERMINED FROM THIS DATA: it would require trial-by-trial mapping of neural activity onto behavioral choice, and IN LIEU OF SUCH DATA the longer window is chosen for two stated reasons Quotation withheld because this record is not cleared for redistribution. with both reasons named - detection is measured against the masker alone, and the behavioral reaction time falls well after the masker begins Quotation withheld because this record is not cleared for redistribution. A STRENGTH AND A LIMITATION IN ONE SENTENCE: the population neurometric pools every cell, which sits against the rival principle that perception is driven by the most sensitive neurons alone Quotation withheld because this record is not cleared for redistribution. AND THE DIRECTION OF THE OWN BIAS IS SPELLED OUT: because every neuron was tested at its own best frequency, the pooled measure omits the poorly tuned cells a real integrator would receive, and would perform worse if they were included Quotation withheld because this record is not cleared for redistribution. THE VARIABILITY IS ITSELF A POINT OF CORRESPONDENCE: masked thresholds are quite variable IN CONCURRENCE WITH the psychophysical data, where more measures per participant are needed than for forward masking Quotation withheld because this record is not cleared for redistribution. A CORRELATE THAT IS NOT THE CAUSE, SAID PLAINLY: masking correlated with tone-evoked suppression but could occur in its absence, and thus was not the sole driver Quotation withheld because this record is not cleared for redistribution. THE METHOD IS ALIGNED TO THE LITERATURE IT WILL BE COMPARED WITH: stimuli were delivered monaurally to parallel the majority of psychophysical backward masking studies Quotation withheld because this record is not cleared for redistribution. and the inclusion rule is set by the perceptual phenomenon rather than by the recording - only units responding reliably to short tones, because backward masking is reliable only for short tones Quotation withheld because this record is not cleared for redistribution. A POOLING DECISION JUSTIFIED BY THE COMPOSITION OF THE SAMPLE: single and multi-units were pooled BECAUSE multi-units dominated the data set Quotation withheld because this record is not cleared for redistribution. THE anesthetic IS JUSTIFIED BY MECHANISM RATHER THAN WAVED AWAY: urethane acts modestly on multiple receptor systems and allows desynchronised cortical activity, unlike ketamine or pentobarbital Quotation withheld because this record is not cleared for redistribution. AND THE AUTHORS' OWN EARLIER NULL COMPLICATES THE STORY: no age difference in the thresholds of the BEST neurons, suggesting juveniles and adults may not equivalently ACCESS the same sensory information Quotation withheld because this record is not cleared for redistribution. with the developmental interpretation flagged as conditional - IF juveniles integrate over a longer window, they would experience larger dynamic range differences Quotation withheld because this record is not cleared for redistribution. and the locus argued from where the phenomenon is and is not found - backward masking appears in the inferior colliculus but not the auditory nerve or cochlear nucleus, and cannot be peripheral because the signal precedes the masker Quotation withheld because this record is not cleared for redistribution. claim_type: mechanism a second reading reaching the same value. Recorded: mechanism — note: a second reading reaching the same value from a different sentence. Not applied - a person decides. Quotation withheld because this record is not cleared for redistribution. method: neurometric thresholds computed in two analysis windows - one containing only the tone response, one containing the masker response as well a second reading DIFFERING from the recorded value. Recorded: electrophysiology — note: a second reading, verbatim-verified, disagreeing with the value on the record. Not applied - a person decides. Quotation withheld because this record is not cleared for redistribution. phenomenon: backward masking - a higher threshold for a short tone when a masker follows it than for the same tone in silence a second reading DIFFERING from the recorded value. Recorded: auditory backward masking — note: a second reading, verbatim-verified, disagreeing with the value on the record. Not applied - a person decides. Quotation withheld because this record is not cleared for redistribution. extends → Brosch et al. 1998 (backward masking in very-long-latency cortical cells) Quotation withheld because this record is not cleared for redistribution. builds-on → Hartley et al. 2000; Huyck and Wright 2018 (developmental psychophysics of backward masking) Quotation withheld because this record is not cleared for redistribution. builds-on → Rosen et al. 2010 (the authors' own gerbil ACx modulation-detection study) Quotation withheld because this record is not cleared for redistribution. extends → the one prior cortical report, which examined only cells with responses beyond 150 ms rather than standard onset responses Quotation withheld because this record is not cleared for redistribution. confirms → the human finding that backward masked thresholds remain immature into adolescence, now in cortical responses Quotation withheld because this record is not cleared for redistribution. distinguishes-from → forward masking, whose relationship between masker level and threshold shift is tight where this one is not differs in: THE AXIS IS MEASUREMENT VARIABILITY, AND THE CONSEQUENCE IS A SAMPLE-SIZE REQUIREMENT. 'Quotation withheld.' The two paradigms differ in how much data a conclusion costs - so a null in backward masking is weaker evidence than the same null in forward masking, at equal n. Quotation withheld because this record is not cleared for redistribution. builds-on → the inferior colliculus account in which inhibition arriving earlier than excitation lets a later masker suppress an earlier tone Quotation withheld because this record is not cleared for redistribution. qualifies → its own population measure, which pools cells that a real downstream integrator would not receive in the same proportions differs in: THE AXIS IS WHICH CELLS THE POPULATION MEASURE POOLS. 'Quotation withheld.' The measure is not wrong - it describes a population no downstream neuron ever receives, because the recording selected for best frequency. A sampling decision that changes what the number is a number OF. Quotation withheld because this record is not cleared for redistribution. reconciles → an earlier null on the best neurons, by proposing that the difference lies in access to the information rather than its encoding Quotation withheld because this record is not cleared for redistribution. forward masking —distinct-from→ backward masking forward masking backward masking strength of the relation: 1 Quotation withheld because this record is not cleared for redistribution. backward masking —part-of→ inferior colliculus backward masking inferior colliculus strength of the relation: 1 · note: THE LOCUS ARGUED FROM WHERE IT IS AND IS NOT FOUND: present in the inferior colliculus, absent in the auditory nerve and cochlear nucleus, and impossible peripherally because the signal precedes the masker 2026-08-20 the project re-read worst chars/edge queue): WRONG-TYPE - the sentence says backward masking has been DEMONSTRATED IN the inferior colliculus. That is a location where a phenomenon was recorded, not a part-whole relation - backward masking is not part of a brain region. Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but backward masking 'HAS BEEN DEMONSTRATED IN' the inferior colliculus; part-of is loose. Quotation withheld because this record is not cleared for redistribution. cochlear nucleus —contrasted-with→ inferior colliculus cochlear nucleus inferior colliculus strength of the relation: 1 · note: re-read worst chars/edge queue): SOUND - the sentence does contrast them: forward but NOT backward masking in the cochlear nucleus, BUT backward masking demonstrated in the inferior colliculus. Both endpoints named, contrast explicit, type correct. KEEP. Quotation withheld because this record is not cleared for redistribution. ACx —causes→ perception ACx perception status: the paper's own words: suggesting that · strength of the relation: 1 Audit 2026-09-28: DOUBTFUL - read against its span and kept, but the span says ACx activity relates to masked signal perception; causes is loose. Quotation withheld because this record is not cleared for redistribution. juvenile —contrasted-with→ adult juvenile adult strength of the relation: 1 · note: greater tone-firing suppression AND larger threshold shifts, at both single-cell and population levels Audit 2026-09-28: DOUBTFUL - read against its span and kept, but the span is cut before the juvenile-adult contrast is stated. Quotation withheld because this record is not cleared for redistribution. masker —operationalised-as→ noise masker noise strength of the relation: 1 · note: a 500 ms noise at 30% bandwidth centerd on the neuron's own best frequency, immediately after a 10 ms tone Quotation withheld because this record is not cleared for redistribution. backward masking —part-of→ ACx backward masking ACx strength of the relation: 1 · note: the first assessment for STANDARD, ONSET-RESPONSIVE neurons rather than the long-latency subset of the one prior study Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but the study shows backward masking OCCURS AT the level of primary auditory cortex; part-of is loose. Quotation withheld because this record is not cleared for redistribution. anesthesia —distinct-from→ psychophysical anesthesia psychophysical strength of the relation: 1 Audit 2026-09-28: DOUBTFUL - read against its span and kept, but the span raises anesthesia as a concern for psychophysical comparison; distinct-from is loose. Quotation withheld because this record is not cleared for redistribution. cortex —causes→ suppression cortex suppression strength of the relation: 0.8 · note: the cortical effect may be INHERITED from earlier regions, with cortex possibly magnifying it by reducing rebound excitation Audit 2026-09-28: DOUBTFUL - read against its span and kept, but the span says masked responses may be inherited from earlier regions; causes is loose. Quotation withheld because this record is not cleared for redistribution. TrialWin —contrasted-with→ ToneWin TrialWin ToneWin strength of the relation: 1 · note: AND THE TWO WINDOWS GIVE DIFFERENT NUMBERS: 18-43 dB against 13-16 dB in adults, with human psychophysics at 20-35 dB Quotation withheld because this record is not cleared for redistribution. tone —contrasted-with→ masker tone masker strength of the relation: 1 Audit 2026-09-28: DOUBTFUL - read against its span and kept, but tone-alone and tone+noise functions were compared; contrasted-with is loose. Quotation withheld because this record is not cleared for redistribution. Mann-Whitney U test Mann-Whitney U test Quotation withheld because this record is not cleared for redistribution. Wilcoxon signed-rank test Wilcoxon signed-rank test Quotation withheld because this record is not cleared for redistribution. Spearman rank correlation Spearman rank correlation Quotation withheld because this record is not cleared for redistribution. Fisher's exact test Fisher's exact test Quotation withheld because this record is not cleared for redistribution. ANCOVA (nonparametric ranked mixed model) ANCOVA (nonparametric ranked mixed model) Quotation withheld because this record is not cleared for redistribution. bootstrap bootstrap Quotation withheld because this record is not cleared for redistribution. confidence interval confidence interval Quotation withheld because this record is not cleared for redistribution. principal component analysis principal component analysis Quotation withheld because this record is not cleared for redistribution. standard error standard error Quotation withheld because this record is not cleared for redistribution. percentiles / box plot summary percentiles / box plot summary about this quote: This quote ends with the stray word 'To', the first word of the next sentence. It is not trimmed, because the quote without it occurs more than once in the paper's text and could not be tied to one place. The claim is carried by the sentence before 'To'. Quotation withheld because this record is not cleared for redistribution. principal component analysis principal component analysis Quotation withheld because this record is not cleared for redistribution. correlation correlation Quotation withheld because this record is not cleared for redistribution. Most auditory cortex neurons required a louder tone to be detected when a noise masker immediately followed the tone, demonstrating backward masking in ordinary onset-responsive cortical cells. Quotation withheld because this record is not cleared for redistribution. Cortical backward masking arises from two things at once: the masker suppresses the tone-evoked response, and it raises the baseline so that the dynamic range available for detecting the tone shrinks. Quotation withheld because this record is not cleared for redistribution. Juvenile units showed significantly larger masked threshold shifts than adult units under both analysis windows. Quotation withheld because this record is not cleared for redistribution. Tone-evoked firing was suppressed by the masker more strongly in juveniles than in adults under both analysis windows. Quotation withheld because this record is not cleared for redistribution. The masker-induced reduction of dynamic range was the same size in juveniles and adults, so the age difference in masking was not driven by dynamic range. Quotation withheld because this record is not cleared for redistribution. Units that gave no response at all to the noise alone still showed significant masked threshold shifts, so a response to the masker is not required for backward masking. Quotation withheld because this record is not cleared for redistribution. Population threshold shifts computed over the whole trial (~18-43 dB in adults) matched human psychophysical backward-masking shifts far better than shifts computed over the narrow tone window (~13-16 dB). Quotation withheld because this record is not cleared for redistribution. In units that did respond to the noise alone, the preceding tone significantly suppressed the noise-evoked firing, i.e. forward masking occurred alongside backward masking in both age groups. Quotation withheld because this record is not cleared for redistribution. Pooling all units into a population neurometric also produced larger threshold shifts for juveniles than for adults under both windows. Quotation withheld because this record is not cleared for redistribution. Within the narrow tone window, the loss of dynamic range predicted the masked threshold shift only in juveniles, suggesting juveniles rely more on dynamic range for detection. Quotation withheld because this record is not cleared for redistribution. The masker caused only a small delay in first-spike latency in both age groups. Quotation withheld because this record is not cleared for redistribution. backward masking has a longer maturational trajectory than many other auditory percepts, and its neural correlates are not well described at any developmental stage Quotation withheld because this record is not cleared for redistribution. AND THE TWO WINDOWS GIVE DIFFERENT ANSWERS: neural threshold shifts match human psychophysics better when the longer window is used Quotation withheld because this record is not cleared for redistribution. THE ANALYSIS WINDOW IS A CHOICE, WITH THE REASONS GIVEN BEFORE THE RESULT: one isolates backward masking uncontaminated by forward masking, the other includes the masker response Quotation withheld because this record is not cleared for redistribution. THE LOCUS ARGUED FROM WHERE IT IS AND IS NOT FOUND: present in inferior colliculus, absent in auditory nerve and cochlear nucleus, impossible peripherally because the signal precedes the masker Quotation withheld because this record is not cleared for redistribution. with variability itself taken as INDICATIVE of central contributions, being greater in backward than forward masking Quotation withheld because this record is not cleared for redistribution. the area was chosen because inactivating it impairs temporal discrimination and because human imaging ties it to conscious masked detection Quotation withheld because this record is not cleared for redistribution. juvenile neurons showed both greater tone-firing suppression and larger threshold shifts, at single-cell and population levels Quotation withheld because this record is not cleared for redistribution. A POOLING DECISION JUSTIFIED BY THE COMPOSITION OF THE SAMPLE: single and multi-units pooled BECAUSE the multi-units dominated Quotation withheld because this record is not cleared for redistribution. THE METHOD IS ALIGNED TO THE LITERATURE IT WILL BE COMPARED WITH: monaural delivery, to parallel the majority of psychophysical studies Quotation withheld because this record is not cleared for redistribution. AND THE INCLUSION RULE IS SET BY THE PERCEPT: only units responding reliably to short tones, because backward masking is reliable only for short tones Quotation withheld because this record is not cleared for redistribution. the masker was a 500 ms noise at 30% bandwidth centerd on each neuron's own best frequency Quotation withheld because this record is not cleared for redistribution. this is the first assessment of backward masking in STANDARD onset-responsive cortical neurons, and both coding elements contribute Quotation withheld because this record is not cleared for redistribution. with the two elements dissociating across development - larger suppression in juveniles but no difference in dynamic range reduction Quotation withheld because this record is not cleared for redistribution. THE anesthetic IS JUSTIFIED BY MECHANISM: urethane acts modestly on several receptor systems and allows desynchronised activity closer to the awake state Quotation withheld because this record is not cleared for redistribution. THE VARIABILITY IS ITSELF A POINT OF CORRESPONDENCE with the psychophysics, unlike the tight relationship seen for forward masking Quotation withheld because this record is not cleared for redistribution. A CORRELATE THAT IS NOT THE CAUSE, SAID PLAINLY: suppression correlated with masking but could occur in its absence Quotation withheld because this record is not cleared for redistribution. a shorter latency for inhibition than excitation lets the later masker suppress the earlier tone, and predicts the negative correlation observed Quotation withheld because this record is not cleared for redistribution. so the cortical effect may be inherited from earlier regions, with cortex possibly magnifying it Quotation withheld because this record is not cleared for redistribution. the backgrounds were chosen deliberately to match how a listener's two thresholds are compared Quotation withheld because this record is not cleared for redistribution. and the dynamic range correlates with masking ONLY in juveniles and ONLY in the narrow window Quotation withheld because this record is not cleared for redistribution. THE CORRECT WINDOW CANNOT BE DETERMINED FROM THIS DATA: it would need trial-by-trial mapping of activity onto behavioral choice Quotation withheld because this record is not cleared for redistribution. IN LIEU OF SUCH DATA the longer window is chosen for two named reasons - the comparison is against the masker alone, and the reaction time falls after masker onset Quotation withheld because this record is not cleared for redistribution. 18-43 dB of shift in the longer window against 13-16 dB in the narrow one, with human psychophysics at 20-35 dB Quotation withheld because this record is not cleared for redistribution. A STRENGTH AND A LIMITATION IN ONE SENTENCE, with the rival lower-envelope principle named Quotation withheld because this record is not cleared for redistribution. AND THE DIRECTION OF THE OWN BIAS SPELLED OUT: testing every neuron at its own best frequency makes the pooled measure optimistic Quotation withheld because this record is not cleared for redistribution. AND THE AUTHORS' OWN EARLIER NULL COMPLICATES IT: no age difference in the best neurons, so the difference may be in ACCESS rather than encoding Quotation withheld because this record is not cleared for redistribution. children LISTEN LATE with respect to a signal, and may be integrating over a longer window than adults Quotation withheld because this record is not cleared for redistribution. with the developmental interpretation flagged as conditional - IF juveniles integrate longer, they WOULD see larger dynamic range differences Quotation withheld because this record is not cleared for redistribution. and the slow maturation attributed to inhibition, which decays more slowly and summates more in young neurons Quotation withheld because this record is not cleared for redistribution. the differential signal suppression could contribute to the large age-related threshold differences seen in psychophysical backward masking, about 25-dB differences around age 9 and still about 10-dB differences by age 15 Quotation withheld because this record is not cleared for redistribution. and the whole point is stated plainly - detection deficits correlate with problems in speech processing Quotation withheld because this record is not cleared for redistribution. ToneWin and TrialWin analysis windows ToneWin and TrialWin analysis windows Quotation withheld because this record is not cleared for redistribution. dynamic range dynamic range Quotation withheld because this record is not cleared for redistribution. encoding time window encoding time window Quotation withheld because this record is not cleared for redistribution. threshold shift threshold shift Quotation withheld because this record is not cleared for redistribution. pooling neurometric pooling neurometric Quotation withheld because this record is not cleared for redistribution. lower envelope principle lower envelope principle Quotation withheld because this record is not cleared for redistribution. backward masking backward masking Quotation withheld because this record is not cleared for redistribution. window window Quotation withheld because this record is not cleared for redistribution. lower envelope lower envelope Quotation withheld because this record is not cleared for redistribution. ToneWin ToneWin Quotation withheld because this record is not cleared for redistribution. BF BF Quotation withheld because this record is not cleared for redistribution. masker level masker level Quotation withheld because this record is not cleared for redistribution. tone level tone level Quotation withheld because this record is not cleared for redistribution. age group age group Quotation withheld because this record is not cleared for redistribution. masked tone threshold shift masked tone threshold shift Quotation withheld because this record is not cleared for redistribution. tone-evoked firing rate suppression tone-evoked firing rate suppression Quotation withheld because this record is not cleared for redistribution. threshold threshold Quotation withheld because this record is not cleared for redistribution. dynamic range dynamic range Quotation withheld because this record is not cleared for redistribution. suppression suppression Quotation withheld because this record is not cleared for redistribution. window window Quotation withheld because this record is not cleared for redistribution. n = 16 adults, n = 18 juveniles — gerbils in each age group and their postnatal-day ranges Quotation withheld because this record is not cleared for redistribution. n = 42 / n = 40 — cortical units recorded in adults and in juveniles Quotation withheld because this record is not cleared for redistribution. ToneWin: P = 0.003; TrialWin: P = 0.013 — Fisher's exact test of elevation showing greater masking in juveniles than adults Quotation withheld because this record is not cleared for redistribution. ToneWin: adult, 15, 13, and 16 dB; juvenile, 21, 19, and 15 dB; TrialWin: adult, 18, 43, and 43 dB; juvenile, 28, 48, and 48 dB — population neurometric threshold shifts at low, mid and high masker levels for each age group and window Quotation withheld because this record is not cleared for redistribution. ~20–35 dB — human psychophysical backward-masked threshold shifts under comparable masking parameters, the benchmark for the neural shifts Quotation withheld because this record is not cleared for redistribution. 65% — detection criterion on the neurometric function used to define a unit's tone detection threshold Quotation withheld because this record is not cleared for redistribution. >50% — share of units showing masked threshold shifts of about 12-15 dB even under the narrow tone window Quotation withheld because this record is not cleared for redistribution. 1,000 — bootstrap resamples drawn per tone level to compute percent-correct detection Quotation withheld because this record is not cleared for redistribution. 13–16 dB — the adult threshold shift measured in the narrow window against 18-43 dB in the longer one - the same neurons, two windows, and only the second matches the 20-35 dB of human psychophysics Quotation withheld because this record is not cleared for redistribution. 50% of trials — the response reliability a unit had to reach to be recorded at all, a selection set by the perceptual phenomenon rather than by the recording Quotation withheld because this record is not cleared for redistribution. ~25-dB — the human age difference in backward masked thresholds around age nine, still about 10 dB by fifteen Quotation withheld because this record is not cleared for redistribution.

The full text of this article is not redistributable, so it is not included here. The evidence sentences are withheld with it; the tag layer and its grounding status remain. The article itself is at https://doi.org/10.1152/jn.00114.2018.